Office Chair Foot Base

ABSTRACT

An office chair foot base providing to support an office chair has a top end disposed towards the office chair, and a bottom end disposed opposite to the top end towards the ground. The office chair foot base comprises a main boy and a plurality of legs. The main boy includes an interior wall formed circularly and a connecting portion connecting to the interior wall at the bottom end. The plurality of legs formed radially extending opposite to the interior wall to a radial extent. Each of the plurality of legs includes a joining portion formed at the bottom end. The joining portion connects with the connecting portion.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an office chair foot base and, in particular, to an office chair foot base providing higher structural strength and lighter.

2. Description of the Related Art

U.S. Pat. No. 4,767,159 shows an office chair that includes a base member having four or five legs. The legs can be installed with roller means, which provide the office chair with the desirable mobility. However, the legs are solid. Although the solid legs provide higher structural strength, but the solid legs are heavier, so that it is inconvenient for carrying, and the manufacture cost is increased.

FIG. 7 shows a conventional office chair foot base 3 providing to support an office chair and mounting a plurality of rollers. The office chair foot base 3 has a top end 301 disposed towards the office chair, and a bottom end 302 disposed opposite to the top end 301 towards the ground. The office chair foot base 3 includes a main body 31 enabling to be installed to an office chair support rod (not shown), a plurality of legs 32 radially extending from the main body 31 to a radial extent. The main body 31 and each of the plurality of leg 32 are integrally formed and have a connection A defined therebetween at the top end 301. Each of the plurality of legs 32 includes an assembling portion 321, two side walls 322 extending along a fictitious extending axis X, and a plurality of ribs 323 formed between the side walls 322 disposed opposite to each other. Each assembling portion 321 is able to install to a roller providing the office chair with the desirable mobility. In order to retain the higher structural strength and lighter, the office chair foot base 3 is not solid, but includes the plurality of ribs 323 to maintain the structural strength of the office chair foot base 3. Furthermore, the main body 31 defines a central axis K extending through the top end 301 to the second end 302.

Generally, the prior art office chair foot base 3 suffers a problem in that the connection A cannot enable loads, i.e., a pressure along the central axis K produced by the weight of a sitter, to be transmitted to the main body 31 and each of the plurality of legs 32. The main body 31 and each of the plurality of legs 32 are deformed along the fictitious extending axis X (as shown by the arrows), thereby causing the main body 31 at the bottom end 302 radially departed form the office chair support rod along the central axis K, so that the main body 31 and each of the plurality of legs 32 to experience bending loads in the operation thereof to generate the connection A broken.

The present invention is, therefore, intended to obviate or at least alleviate the problems encountered in the prior art.

SUMMARY OF THE INVENTION

According to the present invention, an office chair foot base providing to support an office chair has a top end disposed towards the office chair, and a bottom end disposed opposite to the top end towards the ground. The office chair foot base comprises a main boy and a plurality of legs. The main boy includes an interior wall formed circularly and a connecting portion connecting to the interior wall at the bottom end. The plurality of legs formed radially extending opposite to the interior wall to a radial extent. Each of the plurality of legs includes a joining portion formed at the bottom end. The joining portion connects with the connecting portion.

It is an object of the present invention to provide an office chair foot base that has an increased structural strength over the conventional office chair foot base.

It is another object of the present invention to provide an office chair foot base is integrally formed of plastic lighter than the conventional solid office chair foot base

It is yet another object of the present invention to provide an office chair foot base is capable of installing a cap, so that the appearance of the office chair foot base is not only simple and terse, but also retains higher structural strength.

Other objects, advantages, and new features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanied drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The illustrative embodiment may best be described by reference to the accompanying drawings where:

FIG. 1 is a perspective view of an office chair foot base in accordance with the present invention.

FIG. 2 is a vertical view of the office chair foot base of FIG. 1.

FIG. 3 is a bottom view of the office chair foot base of FIG. 1.

FIG. 4 is a cross sectional view of the office chair foot base of FIG. 1.

FIG. 5 is a cross sectional view showing the office chair foot base of FIG. 1 deformed under a load.

FIG. 6 is a cross sectional view showing a cap installed to the office chair foot base of FIG. 1.

FIG. 7 is a cross sectional view showing a conventional office chair foot base deformed under a load.

All Figures are drawn for ease of explanation of the basic teachings of the present invention only; the extensions of the Figures with respect to number, position, relationship, and dimensions of the parts to form the preferred embodiments will be explained or will be within the skill of the art after the following teachings of the present invention have been read and understood. Further, the exact dimensions and dimensional proportions to conform to specific force, weight, strength, and similar requirements will likewise be within the skill of the art after the following teachings of the present invention have been read and understood.

Where used in the various Figures of the drawings, the same numerals designate the same or similar parts. Furthermore, when the terms “first”, “second”, “third”, “inner”, “outer”, “side”, “end”, “portion”, “section”, “longitudinal”, “clockwise”, “counterclockwise”, and similar terms are used herein, it should be understood that these terms have reference only to the structure shown in the drawings as it would appear to a person viewing the drawings and are utilized only to facilitate describing the invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

An office chair foot base 1 according to the preferred teachings of the present invention is shown in the drawings. In the preferred forms shown in FIGS. 1 to 6, the office chair foot base 1 providing to support an office chair (not shown) has a top end 101 disposed towards the office chair and a bottom end 102 disposed opposite to the top end 101 towards the ground. The office chair foot base 1 includes a main body 10 enabling to be installed to an office chair (not shown), a plurality of legs 20 radially extending from the main body 10 to a radial extent. The main body 10 and each of the plurality of leg 20 are integrally formed of plastic to reduce the weight of the office chair foot base 1 and have a connection B defined therebetween at the bottom end 102.

The main body 10 includes an interior wall 11 formed circularly, an exterior wall 12 formed circularly and disposed around the interior wall 11, and a connecting portion 13 formed between the interior wall 11 and the exterior wall 12 at the bottom end 102. The main body 10 further includes a gap 14 formed among the interior wall 11, the exterior wall 12 and the connecting portion 13. The interior wall 11 has a hole 111 enclosed thereby and enabling to be installed to an office chair support rod (not shown).

The plurality of legs 20 radially extends from a surface of the exterior wall 12 opposite to the interior wall 11 to a radial extent. Each of the plurality of legs 20 includes a joining portion 21 formed at the bottom end 102 and an assembling portion 22 disposed opposite to the joining portion 21. The joining portion 21 defines the connection B. The joining portion 21 and assembling portion 22 are formed at two opposite ends of each of the plurality of legs 20. Each joining portion 21 of the plurality of legs 20 connects with the connecting portion 13 of the main body 10, in a perfect form, each joining portion 21 of the plurality of legs 20 and the connecting portion 13 of the main body 10 are integrally formed. Each of the plurality of assembling portions 22 is able to installing to a roller providing the office chair with the desirable mobility. Each of the plurality of legs 20 includes two side walls 23 extending along a fictitious extending axis Y and connecting the exterior wall 12 of the main body 10 and the assembling portions 22 at two opposite ends of each side wall 23. Each of the plurality of legs 20 has a plurality of ribs 24 formed between an inside surface of the side wall 23 and an inside surface of the other side wall 23. Each of the plurality of legs 20 further includes a space 25 formed among the exterior wall 12 of the main body 10, the joining portion 21 and one of the plurality of ribs 24 disposed opposite to the exterior wall 12. Furthermore, the main body 10 defines a central axis C extending through the top end 101 to the second end 102.

Each joining portion 21 connects with the connecting portion 13 at the bottom end 102. When a pressure F presses on the main body 10 along the central axis C produced by the weight of a sitter, the interior wall 11 and the exterior wall 12 both are deformed towards the central axis C at the top end 101 radially (as shown by the arrows in FIG. 5), and the interior wall 11 abuts to the office chair support rod. Further, the gap 14 and the space 25 provide a buffer area for the deformation of the exterior wall 12 and each of the plurality of ribs 24, so that it reduces the stress concentration between the connecting portion 13 and each joining portion 21 to avoid the connection B to be broken.

Additional, the office chair foot base 1 is capable of installing a cap 2 at the top end 101. The cap 2 is made in the shape of a disk, and includes a first installing portion 201 and a second installing portion 202 both formed towards the top end 101 of the office chair foot base 1. The first installing portion 201 is received in and seals the gap 14, and the second installing portion 202 is received in and seals the space 25, so that the gap 14 and the space 25 are not exposed. The appearance of the office chair foot base 1 is not only simple and terse, but also retains higher structural strength.

Thus since the invention disclosed herein may be embodied in other specific forms without departing from the spirit or general characteristics thereof, some of which forms have been indicated, the embodiment described herein is to be considered in all respects illustrative and not restrictive. The scope of the invention is to be indicated by the appended claims, rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are intended to be embraced therein. 

1. An office chair foot base providing to support an office chair on a ground comprising: a top end disposed towards and facing the office chair; a bottom end disposed opposite to the top end towards and facing the ground; a main boy including an interior wall formed circularly and a connecting portion connecting to the interior wall at the bottom end; and a plurality of legs formed radially and extending opposite to the interior wall to a radial extent, with each of the plurality of legs including a joining portion formed at the bottom end, with the joining portion connecting with the connecting portion.
 2. The office chair foot base as claimed in claim 1, wherein the main body includes an exterior wall formed circularly and disposed around the interior wall.
 3. The office chair foot base as claimed in claim 2, wherein the main body defining a central axis extending through the top end to the bottom end, wherein the office chair foot base subject to a pressure, with pressure pressing on the main body along the central axis, with the interior wall and the exterior wall both deformed towards the central axis at the top end radially, with the interior wall abutting against the office chair support rod.
 4. The office chair foot base as claimed in claim 2, wherein the main body and each of the plurality of leg are integrally formed of one-piece plastic to reduce the weight of the office chair foot base and have a connection defined therebetween at the bottom end.
 5. The office chair foot base as claimed in claim 4, wherein each of the plurality of legs includes an assembling portion disposed opposite to the joining portion, with each of the plurality of assembling portions to be capable of installing to a roller providing the office chair with the desirable mobility.
 6. The office chair foot base as claimed in claim 5, wherein each of the plurality of legs includes two side walls extending along a fictitious extending axis, with each side wall connecting the exterior wall of the main body and the assembling portions at two opposite ends of each side wall.
 7. The office chair foot base as claimed in claim 6, wherein each of the plurality of legs has a plurality of ribs formed between an inside surface of the side wall and an inside surface of the other side wall.
 8. The office chair foot base as claimed in claim 1, wherein the interior wall includes a hole enclosed thereby, with the hole enabling to be installed to an office chair support rod.
 9. The office chair foot base as claimed in claim 7, wherein the main body further includes a gap formed among the interior wall, the exterior wall and the connecting portion, wherein each of the plurality of legs further includes a space formed among the exterior wall of the main body, the joining portion and one of the plurality of ribs disposed opposite to the exterior wall, wherein the gap and the space provide a buffer area for the deformation of the exterior wall and each of the plurality of ribs to avoid the connection to be broken.
 10. The office chair foot base as claimed in claim 9, wherein the office chair foot base is capable of installing a cap at the top end, with the gap and the space being not exposed.
 11. The office chair foot base as claimed in claim 10, wherein the cap is made in the shape of a disk.
 12. The office chair foot base as claimed in claim 10, wherein the cap includes a first installing portion and a second installing portion both formed towards the top end of the office chair foot base, with the first installing portion received in and seals the gap, with the second installing portion received in and seals the space. 